JP2007160431A - Cutting method using wire saw and cut work receiving member of wire saw - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting method using a wire saw which prevents wafers from sticking to each other in cutting, reforms cutting with good accuracy, prevents occurrence of cracks in the wafer in cutting, and efficiently separates wafers sheet by sheet to improve the cleaniness of the wafer. <P>SOLUTION: In this cutting method using a wire saw, a wire A of a wire row wound between work rollers 10 is reciprocated or run in one direction at high speed, and a workpiece B is pressed to the wire row to be slitted into a number of wafers. A cassette type receiving member 27 in which a number of support wires 34 are provided at the same pitch as that of wires of the wire row, is disposed right under the wire row for cutting the workpiece B, and the wafers (b) slitted from the workpiece B by the wire A are stored in a sheet state between the respective support wires 34 of the receiving member 27. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cutting method using a wire saw and a cutting work receiving member for a wire saw, more specifically, a method for separating a cut workpiece into pieces when cutting a workpiece with a wire saw, and a receiving member for receiving the cutting workpiece in a suitably separated state. About.

  In the wire saw, the wire drawn from the supply-side reel is guided to a tension mechanism and a load cell for measuring the tension via a traverser and a guide pulley, and then wound around a plurality of at least two work rollers to form a wire row, After that, it is wound around the collection side reel.

  The above-described wire row between the work rollers is reciprocated at a high speed or moved in one direction, and the wire row contains a hard slurry such as SiC or diamond, or a water-soluble slurry solution for easy cleaning. The workpiece is pressed against the wire row while supplying the workpiece, and the workpiece is simultaneously cut into a plurality of wafers. In addition, the wire which fixed the diamond grain with resin etc. is also performed.

  In the cutting of workpieces using the wire saw as described above, the demand for cutting silicon ingots for solar cells and the like as a workpiece has been increasing recently. However, as a cost reduction, the thickness of the wafer is required to be 200 μm or less. The spur is on.

  As described above, as the thickness of the cut-up becomes thinner, it becomes difficult to handle the wafer after cutting, and the yield is deteriorated due to the cracking of the wafer before the next cleaning process.

  Conventionally, as shown in FIG. 9 (a), the work cutting method using a wire saw is performed by attaching a work B such as silicon or ingot to the work processing table 51 through a dummy member 52 using a carbon or glass plate with an adhesive. The workpiece B is fixed and pressed toward the wire A in the wire row, and the workpiece B is cut into strips by cutting up to the dummy member 52 as shown in FIG. 9B, and the wafer b is cut out. Yes.

  For this reason, the wafer b cut out by the wire saw is preliminarily washed in the strip state bonded to the dummy member 52 used at the time of cutting to remove the slurry liquid (abrasive liquid) 53, and then the wafer b and the dummy member 52 are bonded together. Single-wafer separation is performed by peeling off the parts or peeling them one by one by hand.

  However, the method of cutting the work into strips creates a gap between the wafers with a wire diameter of, for example, 160 μm to recently 80 μm, and slurry liquid accumulates in this gap, and the gap is reduced by the surface tension of this slurry liquid. However, the wafer cut out to a thickness of about 100 μm is flexed to bend significantly at the outermost wafer b as shown in FIG. 9B, and the wafer receiving the weight of the slurry liquid 53 is slightly vibrated. There is a problem of falling off at.

  Further, in the strip-shaped cutting method, since the cut wafer b remains adhered to the dummy member 52, the workpiece must be lifted up and removed from the wire A after being cut. At this time, there is also a problem that the cut surface of the wafer comes into contact with the wire and the cut surface of the wafer is damaged.

In order to solve such a problem caused by the strip-shaped cutting, a dummy member fixed to the work fixing table and a dummy member fixed to the work are attached to the work fixing table to fix the work to the work fixing table. By fixing the workpiece with a space in between, and cutting the workpiece side dummy member together with the workpiece into the space, the wafer is separated from the workpiece fixing table side dummy member at the same time as the cutting is completed. There has been proposed a cutting method in which a wafer that is dropped by cutting is received by a work holder to separate the wafer into single wafers (see, for example, Patent Document 1).
JP 2000-326324 A

  By the way, the cutting method of dropping the wafer simultaneously with the end of cutting and receiving the wafer with the workpiece receiver is such that the wire is positioned at the end end side of the workpiece and the cutting start end side is free as the cutting approaches the final stage when cutting the wafer. Therefore, the cutting start ends of the wafers are stuck to each other by the surface tension of the slurry liquid.

  When cutting is performed in such a state, especially in a down cut type wire saw in which a workpiece is pressed from above the wire row and cut, the cut and separated wafer is re-connected to the adjacent wafer when dropped due to the surface tension of the slurry liquid. Wafers that are attached and stuck on multiple wafers are cracked by slight vibration during cutting due to their own weight and the weight of the slurry liquid, and even when multiple wafers fall at once, cracks occur, There is a problem that the yield significantly deteriorates.

  Also, due to the sticking of the wafer edge during cutting, the wafer bends during cutting, the cutting accuracy deteriorates, and the dropped wafer falls to the next, and the adjacent wafer is cracked or deformed by the weight of the overlapping wafers. There is also a problem.

  Furthermore, in order to clean the wafer attached with the surface tension of the slurry liquid, it is necessary to break down the surface tension. However, a considerably strong cleaning power is required, which causes damage to the wafer and a strong cleaning liquid. This requirement causes problems in terms of environment and cost. Furthermore, since the wafer is thinned, the wafer may be damaged at the time of peeling particularly when the peeling is performed manually.

  In addition, when a space is provided between the dummy members in fixing the workpiece to the workpiece fixing table, the workpiece vibrates when cutting with a wire, and it is difficult to perform accurate cutting.

  Accordingly, the object of the present invention is to solve the above-mentioned problems, preventing sticking between wafers at the time of cutting, cutting with high accuracy, and preventing the occurrence of cracking of the wafer at the time of cutting, An object of the present invention is to provide a wire saw cutting method and a wire saw cutting work receiving member that can efficiently separate wafers to improve wafer cleaning performance and reduce costs during cleaning.

  In order to solve the above problems, the invention of a cutting method is characterized in that a wire row is formed by winding a wire many times around at least two work rollers, and the wire of the wire row is reciprocated at a high speed or travels in one direction. In a cutting method using a wire saw that presses a workpiece against a wire row and cuts the workpiece into a plurality of wafers, a plurality of partition members are arranged at the same pitch as the wires of the wire row at a position immediately below the wire row that cuts the workpiece. The structure which arrange | positions the provided receiving member, and isolate | separates and accommodates the cutting workpiece cut out from the workpiece | work with the wire between each partition member of a member is employ | adopted.

  In order to press the work against the wire row, the work is attached to the work fixing table to which the work is attached. The dummy member fixed to the work fixing table and the dummy member fixed to the work are brought into close contact with each other. It can be carried out by bonding and fixing outside the range.

  Further, the invention of the cutting work receiving member forms a wire row by winding a wire many times around at least two work rollers, and the wire in the wire row is reciprocated at a high speed or moved in one direction. Is a receiving member that separates and stores the cut workpiece cut out from the workpiece by the wire, with respect to the wire saw that cuts the workpiece into a number of wafers by pressing against the wire saw. The receiving member is formed by winding a support wire at the same number and the same pitch as the wires in the wire row of the wire saw between the plurality of groove rollers provided on the bottom plate, and the receiving member cuts the workpiece. A configuration is adopted in which each of the support wires is positioned directly below the wires in the wire row at a lower position of the wire row.

  The plurality of groove rollers are provided on the bottom plate in a horizontal triangle arrangement, and the portions located above and below the support wire wound around the three groove rollers are inclined reversely. Can be.

  Here, the receiving member can be attached to and detached from the wire saw in a cassette manner, and the support wire wound around the groove roller has the same diameter as the wire saw wire.

  The wafer cut by the wire row of the wire saw fits from the cutting side tip between the support wires located immediately below, preventing deformation due to bending of the wafer, and separating adjacent wafers without sticking to each other. Thus, the cut wafer can be taken out from the wire saw together with the receiving member.

  According to the present invention, a cutting work that has been cut out from a workpiece by a wire, in which receiving members provided with a number of partition members at the same pitch as the wires in the wire row are arranged immediately below the wire row that cuts the workpiece in the wire saw. Since the receiving member is separated and stored between the partition members, the wafer cut by the wire row can be accommodated from the cutting-side tip between the partition members positioned immediately below, and deformation due to bending of the wafer can be prevented. Cutting accuracy is improved, and adjacent wafers can be reliably separated without sticking with slurry liquid.

  In addition, by separating the cut wafers one at a time, there is no occurrence of cracks due to dropping at the end of cutting or sticking of wafers in the stored state, and wafer cleaning is easy and handling becomes easy. In addition, the wafer is not damaged at the time of sheet separation.

  Furthermore, since the workpiece is fixed to the workpiece fixing table, the dummy member fixed to the workpiece fixing table and the dummy member fixed to the workpiece are brought into close contact with each other, and both the dummy members are bonded and fixed outside the range of the workpiece. The workpiece is not vibrated at the time of cutting, and the workpiece can be cut with high precision. By cutting the dummy member fixed to the workpiece at the time of cutting the workpiece, the wafer can be separated at the same time as the cutting.

  In addition, the groove rollers of the cutting work receiving member are provided in a triangular arrangement on the bottom plate, and the portions positioned above and below the support wire wound around the periphery of the three groove rollers are reversely inclined. As a result, the wafer can be sequentially guided from the front end side of the cut wafer with a support wire and guided into the receiving member, and the wafer can be reliably separated and stored.

  Hereinafter, embodiments of the present invention will be described based on illustrated examples.

  FIG. 1 shows the overall structure of a wire saw. A wire A drawn out from a supply-side reel 1 is composed of a supply-side traverser 3 driven by a motor 2 and an encoder 5 and a tension arm 6 via a plurality of guide pulleys 4. After being guided to a tension mechanism 7, a load cell 8 for measuring the tension of the wire A, and a plurality of guide pulleys 9, it is wound many times around two work rollers 10 parallel to both sides at a predetermined interval to form a wire row. Thereafter, a plurality of guide pulleys 11, a load cell 12 for measuring the tension of the wire A, a tension mechanism 15 including an encoder 13 and a tension arm 14, a plurality of guide pulleys 16, and a recovery side traverser driven by a motor 17. 18 is wound around the collection-side reel 19.

  The workpiece fixing table 20 is arranged so as to move up and down by an appropriate driving means (not shown) immediately above the upper wire row wound between the work rollers 10, and the workpiece B attached to the lower surface of the workpiece fixing table 20 is connected to the wire row. It is designed to be pushed down toward.

  The wire A in the wire row between the work rollers 10 described above is reciprocated at a high speed or moved in one direction by a rotational drive by an appropriate driving means (not shown) of the work roller 10, and SiC, diamond, etc. are moved to the wire row by the abrasive nozzle 21. While supplying a slurry liquid containing hard abrasive grains or a water-soluble slurry liquid for facilitating cleaning, the workpiece B is pressed against the wire row and the workpiece B is simultaneously cut into a plurality of wafers. It has become. A wire in which diamond grains are fixed to the wire A with a resin or the like may be used. In this case, cooling water, lubricating liquid, etc. can be used instead of the slurry liquid.

  The workpiece B is attached to the workpiece fixing table 20 to which the workpiece B is attached, as shown in FIGS. 2 and 7, a processing table 22 is provided at the lower portion of the workpiece fixing table 20 so that the position can be adjusted. A dummy member 23 using a carbon or glass plate and a similar dummy member 24 are fixed to the upper surface of the work B using an adhesive 25, and the upper and lower surfaces of both dummy members 23 and 24 are adhered to each other. Both dummy members 23 and 24 are fixed by the adhesive 25 outside the range of the workpiece B.

  When such work B is attached, the processing table 22 and the dummy members 23 and 24 come into close contact with each other, and vibration of the work B when the work is cut can be effectively prevented. In FIG. 7, it is exaggerated for easy understanding.

  In the illustrated example, a case is shown in which two workpiece tables 22 are arranged side by side at the lower portion of the workpiece fixing table 20, and the workpieces B are attached to the lower portion of each workpiece table 22, thereby simultaneously cutting the two workpieces B. However, it is also possible to cut one workpiece B by using one processing table 22.

  In the wire saw as described above, a fixed frame 26 having a horizontal portion is provided at a lower position between wire rows positioned vertically between the two work rollers 10, and an upper wire for cutting the workpiece B on the fixed frame 26. At a lower position of the row, a receiving member 27 for separating and storing a cut workpiece b (hereinafter referred to as a wafer) cut out from the workpiece B by the wire A and separated into a single wafer is arranged by a cassette system that can be taken out.

  As shown in the figure, in the case of a wire saw that simultaneously cuts two workpieces B, two receiving members 27 are arranged below the wire row so as to be positioned immediately below each workpiece B.

  As shown in FIGS. 2 to 6, the fixed frame 26 is a support in which a vertical machine base 28 that supports a shaft 10 a that transmits a driving force to the work roller 10 and a portion that pivotally supports the tip of the work roller 10 are covered with a cover 29. Both ends along the axial direction of the work roller 10 are fixed to the plate 30, and the receiving member 27 is provided with cassette side plates 32 erected at both ends of the cassette bottom plate 31 placed on the fixed frame 26. A plurality of groove rollers 33 parallel to the work roller 10 are installed between 32, and a support wire 34 serving as a partition member is wound around the outer periphery of the group of groove rollers 33.

  The receiving member 27 has one end abutted against a reference plate 35 provided for determining a reference position on one end side on the upper surface of the fixed frame 26, and is fitted into the other end and the other end of the fixed frame 26. The positioning member 36 is accurately positioned and fixed on the upper surface of the fixed frame 26, and the receiving member 27 can be removed from the fixed frame 26 by removing the positioning member 36.

  Three groove rollers 33 are used and are laid between the cassette side plates 32 so as to form a horizontal isosceles triangle. The support wires 34 wound around the outer periphery of the group of groove rollers 33 are arranged in the upper wire row of the wire saw. The receiving members 27 are wound at the same number and the same pitch as the wires A. The receiving members 27 are positioned and fixed to the fixed frame 26, and the support wires 34 are arranged at the lower positions of the wire rows for cutting the workpiece B. The arrangement is located immediately below the wire A.

  The support wire 34 has the same diameter as the wire A of the wire saw, and the support wire 34 is wound around the outer periphery of the groove roller 33 group in the same number as the wire row on the outer periphery of the groove roller 33. A groove having the same pitch may be formed, and a winding machine may be used as appropriate, and the support wire 34 may be wound along the groove.

  In the receiving member 27, the support wire 34 is arranged in a horizontal isosceles triangle, so that the support wire 34 is positioned up and down with a reverse inclination, and the cut wafer b is supported by the support wire 34 from the front end side. Guided into the receiving member 27 while being sequentially guided, the sheets can be reliably separated and stored.

  In the case of a wire saw that simultaneously cuts two workpieces B, the receiving members 27 on both sides are arranged so that the vertices of the lateral isosceles triangles of the support wire 34 face each other as shown in FIG. In such an arrangement, the upper portions of the support wires 34 are inclined toward each other, so that no interference occurs when the wire A is bent downward during the work cutting operation.

  The above-described cassette bottom plate 31 has a hole 37 that supports the wafer b, and a mesh member 38 is stretched in the hole 37 so that the slurry liquid can easily escape, and a linear buffer member 39 is disposed on the upper surface thereof. By doing so, the dropped wafer b is elastically received and shock is buffered to prevent the wafer b from being damaged.

  The support member in the receiving member 27 is not limited to the horizontal isosceles triangle support wire 34 as shown in the figure. For example, one diagonal or horizontal wire is used on the top and bottom, or on the cassette bottom plate 31, A triangular plate having a thickness equal to the diameter of the wire A can be erected at the same pitch as the wire row.

  Next, a work cutting method using the wire saw of the present invention will be described.

  As shown in FIG. 7A, the work B is fixed to the processing table 22 of the work fixing table 20 in the raised position by using the adhesive 25 through the dummy members 23 and 24, and the upper wire row between the work rollers 10. In a state where the receiving member 27 is positioned and fixed on the lower fixed frame 26, the wire A of the wire row between the work rollers 10 is reciprocated or moved at a high speed, and the work fixing table 20 is lowered to wire the work A. When pressed against the row, as shown in FIG. 7B, the workpiece B is cut by the wire A in the wire row, and a large number of wafers b are cut out simultaneously.

  The cut wafer b enters from the cutting tip between the upper support wires 34 positioned immediately below, and each wafer b is guided downward in a state of being separated by the support wire 34, and with the progress of cutting, the cutting tip. Enters between the lower support wires 34, whereby the wafer b is maintained in a partitioned state, and the wafers b are cut accurately without occurrence of sticking between the wafers b due to the surface tension of the slurry liquid. At the same time, when approaching the end of cutting, the dummy member 23 of the processing table 22 is cut.

  When the work B is attached to the work table 22, the dummy member 23 fixed to the work table 22 and the dummy member 24 bonded to the work B are brought into close contact with each other, and both the dummy members 23 and 24 are out of the cutting range of the work B. Therefore, when cutting to the dummy member 23 of the processing table 22 is performed, the cut portion of the dummy member 24 fixed to the workpiece B is the dummy member 23 fixed to the processing table 22 as shown in FIG. Since they are not bonded, the cut wafer b and the dummy member 24 fall by their own weight while being guided by the support wire 34, and the lower part is supported by the buffer member 39 of the receiving member 27.

  Before the above-described cutting of the workpiece B is completed, the dummy member 24 bonded to the workpiece B is in close contact with the dummy member 23 fixed to the processing table 22, so that the workpiece B is prevented from vibrating during cutting. Can be cut with high accuracy.

  As described above, when the cutting is completed, the workpiece B is separated into wafers b and is held in an upright manner by the support wires 34 of the receiving member 27, so that deformation due to bending is prevented and the separation is performed. The formed wafer b does not reattach to the adjacent wafer b.

  When the cutting of the wafer b is completed in this way, the work fixing table 20 is returned to the raised position, the receiving member 27 on the fixed frame 26 is taken out from between the upper and lower wire rows of the stopped wire saw, and is directly subjected to the next cleaning process. Take. If necessary, rough cleaning may be performed by an appropriate mechanism in the apparatus.

  FIG. 8 shows a method of transferring the wafer b to the cleaning cassette 40 during the cleaning step. The receiving member 27 supporting the wafer b in a single wafer separation state is erected so that the wafer b is positioned vertically. By picking up one wafer at a time in order from the upper wafer b by the suction hand 41, the picked-up wafer b is received by the robot hand 42, and the wafer b is inserted into the cleaning cassette 40 to widen the vertical interval of the wafer b. Ensure that cleaning is possible.

  Since the wafer b is separated and supported by the support wires 34 of the receiving member 27, rough cleaning can be performed while being supported by the receiving member 27, and handling work when removing the wafer b from the receiving member 27 is performed. Can be done easily.

  The dummy member 24 bonded to the wafer b is removed by removing the adhesive 25 using a solvent or hot water in the subsequent process.

Front view showing the overall structure of the wire saw Longitudinal front view with enlarged main parts of wire saw Fig. 2 is a plan view of the wire saw in the direction of arrows III-III. IV-IV arrow side view of FIG. 2 which expanded and shows the arrangement state of a receiving member Enlarged longitudinal front view showing the arrangement of the receiving member (A) is a perspective view which shows the state in the middle of a workpiece | work cutting | disconnection, (b) is a perspective view of the cutting completion state (A) thru | or (c) is a VII-VII arrow side view of FIG. 2 which shows the order of a workpiece | work cutting process. A perspective view showing a cleaning process of a cut wafer Front view showing conventional work cutting method

Explanation of symbols

A wire B work b wafer 1 supply side reel 2 motor 3 supply side traverser 4 guide pulley 5 encoder 6 tension arm 7 tension mechanism 8 load cell 9 guide pulley 10 work roller 10a shaft 11 guide pulley 12 load cell 13 encoder 14 tension arm 15 tension mechanism 16 Guide pulley 17 Motor 18 Collection side traverser 19 Collection side reel 20 Work fixing table 21 Abrasive liquid nozzle 22 Processing base 23 Dummy member 24 Dummy member 25 Adhesive 26 Fixing frame 27 Receiving member 28 Machine base 29 Cover 30 Support plate 31 Cassette bottom plate 32 Cassette side plate 33 Groove roller 34 Support wire 35 Reference plate 36 Positioning member 37 Hole 38 Mesh member 39 Buffer member 40 Cleaning cassette 41 Suction hand 42 Robot hand

Claims (4)

  A wire row is formed by winding a wire many times around at least two work rollers, the wire in the wire row is reciprocated at a high speed or moved in one direction, and the workpiece is pressed against the wire row so that the workpiece is In a cutting method using a wire saw that cuts into a wafer, a receiving member in which a number of partition members are provided at the same pitch as the wires in the wire row is arranged immediately below the wire row that cuts the workpiece, and the wire is cut out from the work by the wire. A cutting method using a wire saw, wherein the cutting work received is separately housed between the partition members of the receiving member.   In order to press the work against the wire row, the work is attached to the work fixing table to which the work is attached. The dummy member fixed to the work fixing table and the dummy member fixed to the work are brought into close contact with each other. The cutting method using a wire saw according to claim 1, wherein the cutting is performed by adhesion and fixing outside the range.   A wire row is formed by winding a wire many times around at least two work rollers, the wire in the wire row is reciprocated at a high speed or moved in one direction, and the workpiece is pressed against the wire row so that the workpiece is A receiving member that is disposed immediately below a wire row that cuts the workpiece with respect to a wire saw that is cut into a wafer shape, and separates and stores the cut workpiece cut out from the workpiece by the wire, and the receiving member is placed on the bottom plate. A support wire is formed between a plurality of groove rollers provided by winding the support wire at the same number and the same pitch as the wires in the wire row of the wire saw, and the receiving member is placed at the lower position of the wire row for cutting the workpiece. A cutting work receiving member for a wire saw in which a wire is arranged to be positioned immediately below a wire in a wire row.   The plurality of groove rollers are provided in a triangular arrangement on the bottom plate in a horizontally oriented triangle, and the portions located above and below the support wire wound around the three groove rollers are reversely inclined. Item 4. A saw workpiece receiving member for a wire saw according to Item 3.

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